Huawei H12-831_V1.0 Exam With Confidence Using Practice Dumps

Comprehensive and Detailed In-Depth Explanation:

1. Understanding Route Targets (RT) and Route Distribution in MPLS VPN

MPLS Layer 3 VPNs (L3VPNs) use BGP to distribute VPN routes across multiple Provider Edge (PE) routers.

Each VPN instance (VRF) is configured with Route Targets (RTs) to control which VPN routes are imported/exported.

Route Distinguishers (RDs) are unique per VRF but do not affect route selection.

2. Analyzing VPN1 Configuration

VPN1 is exporting routes with the following Route Targets (vpn-target values):

100:1

200:1

300:1

Remote VPNs will import these routes only if their import RT list matches one of the exported RTs.

3. Matching Exported RTs with Import RTs in Remote VPNs

Remote VPN

Import RTs

Matches VPN1 Exported RTs (100:1, 200:1, 300:1)?

Accepts the Route?

VPN1

100:1

✅ Matches 100:1

✅ Yes

VPN2

200:1, 400:1

✅ Matches 200:1

✅ Yes

VPN3

100:1, 300:1

✅ Matches 100:1, 300:1

✅ Yes

VPN4

500:1

❌ No match

❌ No

✅ VPN1, VPN2, and VPN3 accept the route.

❌ VPN4 does not accept the route because 500:1 is not in the export list of VPN1.

Final Conclusion:

✅ Correct Answer: VPN1, VPN2, and VPN3 will accept the route.

❌ VPN4 does not accept the route because there is no matching RT.

Thus, the correct answer is:

✅ A. VPN1: Import RT=100:1

✅ B. VPN2: Import RT=200:1, 400:1

✅ C. VPN3: Import RT=100:1, 300:1

❌ D. VPN4: Import RT=500:1 (No match, does not accept the route).

Link-LSA (ID 0.0.0.4):This LSA is originated by each router to describe its link-local IPv6 address and prefixes.The value 0.0.0.4 maps to the interface on R1, which has Router ID 10.0.1.1.✅ So the origin router is 10.0.1.1.

Network-LSA (ID 0.0.0.5):This LSA is generated by the DR on the link. In the diagram, R4 (10.0.4.4) is connected to the shared network (GE0/0/1).✅ So the origin router is 10.0.4.4.

Inter-Area-Prefix-LSA (ID 0.0.0.1):This LSA is used to describe routes from other areas and is generated by an ABR.In this case, R3 (Router ID 10.0.3.3) acts as the ABR.✅ So the origin router is 10.0.3.3.

Intra-Area-Prefix-LSA (ID 0.0.0.2):This references a Network-LSA, and the reference type is 1 (Network-LSA).Since the Network-LSA (0.0.0.5) came from 10.0.4.4, this also must have been generated by R4.✅ So the origin router is 10.0.4.4.

✅ Final Answer Summary:

Number

Origin Router

1

10.0.1.1

2

10.0.4.4

3

10.0.3.3

4

10.0.4.4

Official Huawei Extract:

" Each router in OSPFv3 generates Link-LSAs for each interface. The DR generates Network-LSAs. ABRs generate Inter-Area LSAs, and the Intra-Area-Prefix LSA references either Router or Network LSAs depending on the link type. "

— [Huawei HCIA-Datacom OSPFv3 LSAs Section]